In one of my students case... They would go through internet panic attacks. This pain was not able to function for a while. This pain went on medication and they are much better now, but the attacks still happen. Just not as intense and not as frequent.
My daughter is battling through some anxiety and mild depression. She's on medication and she is seeing a councilor once a week. She had still managed complete a successful mission, is starting her Junior year at BYU, supports herself (server at one of the better restaurants in Provo-Orem, and lives on her own. She does take anxiety meds that have really helped her.
Another thing that really helped my daughter was reading about Tanner Mangum's struggles.